Front end loader having adjustable height control



L. H. CHANT May 20, 1969 FRONT END LOADER HAVING ADJUSTABLE HEIGHTCONTROL Filed NOV. 13. 1967 INVENTOR. flozzara' (i CZazzf May 20, 1969L. H. CHANT FROHT END LOADER HAVING ADJUSTABLE HEIGHT CONTROL Filed Nov.13, 1967 I N VEN TOR.

- Leonard 6! 02am 6.? 5W ATTORNEY y 20, 1969 L. H. CHANT 3,445,020

FRONT END LOADER HAVING ADJUSTABLE HEIGHT CONTROL Filed'Nov. 13. 1967Sheet 3 of s J5 6 INVENTOR 9 leonam' H, Chan? United States Patent3,445,020 FRONT END LOADER HAVING ADJUSTABLE HEIGHT CONTROL Leonard H.Chant, Euclid, Ohio, assignor to General Motors Corporation, Detroit,Mich., a corporation of Delaware Filed Nov. 13, 1967, Ser. No. 682,321

Int. Cl. E02 3/04, 3/40; B62d 21/14 U.S. Cl. 214-768 7 Claims ABSTRACTOF THE DISCLOSURE Rubber-tired front end loaders are used for digging,loading, and limited transportation of material and are usually equippedat the forward end thereof with a boom or lift arm that is hinged nearthe top of the tractor frame. The boom extends forwardly and downwardlyterminating with a pivotally supported bucket which normally experiencesthree motions during the work cycle mentioned above. For example, thebucket can be raised and lowered by lift jacks controlling it throughthe boom, it can be tilted about its support axis on the boom by tiltjacks and linkage, and can be moved fore or aft by movement of thetractor. Except for the last motion, vertical bucket movement isnormally limited in extent between two extreme positions, normallyreferred to as the raised-dump position and the lowered-dig position Inthis connection, the highest possible dumping height and the lowestpossible digging position for the bucket is determined in part by thestroke of the lift jacks and the length of the boom and, in most cases,this has no detrimental effect on the work cycle of the loader. However,there are times when increased productivity and efficiency can berealized if the dump height and the digging depth can be increasedbeyond the design limits of the vehicle.

Accordingly, the objects of the present invention are to provide a frontend loader in which the ground height of the bucket can be varied byraising and lowering the front end of the tractor; to provide asupplemental control for varying the maximum dump height and diggingdepth of a front end loader bucket; to provide a control linkageassociated with the front axle of a front end loader for adjusting theposition of the vehicle frame relative to the front axle of the vehicle;to provide a front axle for a front end loader that is supported formovement relative to the vehicle frame about a transverse horizontalaxis and an axis extending longitudinally of the vehicle under thecontrol of power-operated cylinders, and to provide a suspen sionlinkage for the front axle of a front end loader which permits thevehicle frame to be moved relative to the axle for varying the positionof the bucket so that the depth of cut and also the dumping height canbe increased.

Other objects and advantages of the present invention will be moreapparent from the following detailed description when taken with thedrawings in which:

FIGURE 1 is an elevation view showing a front end loader vehicleequipped with an axle control linkage made in accordance with theinvention;

FIGURE 2 is an enlarged view showing the front end of the loader ofFIGURE 1;

3,445,020 Patented May 20, 1969 FIGURE 3 is a view similar to FIGURE 2and shows the front end of the vehicle in its fully lowered position;

FIGURE 4 is a view similar to FIGURE 3 but shows the vehicle front endin the fully raised position;

FIGURE 5 is a front view of the vehicle as shown in FIGURE 2, and

FIGURE 6 is a view similar to FIGURE 5 but shows the vehicle frametilted above an axis extending longitudinally of the vehicle.

Referring to the drawings and more particularly FIG- URE 1 thereof, anearth-moving front end loader is shown comprising a tractor 10 having anengine (not shown) located in a rear compartment 11 thereof that servesto transmit power through an appropriate gear box 12 forwardly andrearwardly to a front axle 14 and rear axle I6, both of which extendtransversely of the vehicle and rotatably support ground-engaging wheels18. Although not shown, the rear axle 16 is connected to the frame 20 ofthe tractor by a pair of trunnions located fore and aft of the axlehousing so 'as to allow the axle to oscillate about a horizontal axisextending longitudinally of the tractor.

The forward end of the tractor 10 is equipped with a bucket 22 that ispivotally supported by the lower end of a boom or lift arm 24 formovement about a transverse horizontal 'axis passing through a pivotconnection 26. The upper end of the lift arm 24 is pivotally connectedto the top of the tractor frame 20 by pivot connection 28. A bucketcontrol linkage 30 serves to control movement of the bucket 22 about itssupport axi with the boom 24 while a double-acting hydraulic lift jack32, one end of which is mounted to the frame 20 by pivotal connection 34while an intermediate portion thereof is pivotally connected to the boom24 by pivotal connection 36, serves to raise the entire boom 24 formoving the latter between the lowered-dig position, shown in FIGURE 2,and a raised'dump position (not shown).

As best seen in FIGURE 2, the bucket control linkage 30 includes adouble-acting hydraulic tilt jack 38, the cylinder end of which ispivotally connected to the tractor frame 20 by a pivot connection 40.The piston rod 42 of the jack 38 extends forwardly and is pivotallymounted to the upper end of a reversing lever 44, the intermediateportion of which is pivotally supported by the boom 24. The lower end ofthe reversing lever 44 pivotally supports a link 46 that extendsforwardly for pivotal connection with a lever 48. The lever 48, in turn,has the lower end thereof pivotally mounted to the boom 24 while theupper end connects with the bucket 22 through a link 50. Thus, byexpansion or contraction of the tilt jack 38 the position of the bucketis controlled about its pivot connection 26 with the boom 24.

At this juncture, it will be noted that only one side of the loader isshown in FIGURES 1 through 4 of the drawings; however, as seen inFIGURES 5 and 6, similar parts and components (identified bycorresponding numerals) are located on the opposite side of the vehicleand through suitable fluid and mechanical interconnections, such ascross beam 51 for example, are adapted to move in unison for attainingthe desired functions of the bucket and associated mechanism.

As alluded to hereinbefore, the boom 24 and bucket 22 are movable by thelift jack 32 between the lowereddig position, shown in FIGURE 2, and araised-dump position, the latter of which occurs when the lift jack 32is fully expanded causing the boom .24 to pivot about its pivotconnection 28 with the frame 20 and thereby permit the load within thebucket 22 to be dumped within the hopper or body of a truck or othermaterial transporter. As should be apparent, the dumping height of theloader described above will be determined by the length of the boom 24and also the stroke of the lift cylinder 32 as well as the verticaldistance between the pivot connection 28 and the ground. Similarly, thedigging position of the bucket 22 will be determined by the samefactors. There are times, however, when an increase in these fixedlimits could provide the loader with improved operating capabilities andefficiencies heretofore not thought possible with vehicles of this type.The present invention is directed to this end and accomplishes heightcontrol of the front end of the loader and, as a consequence, of thebucket 22 in a manner to be described now.

The front axle 14 includes an axle housing 52- supported by an axlecontrol linkage which includes a pair of laterally spaced A-framemembers 54, each of which is located on one side of the longitudinalaxis of the vehicle. Each A-frame member 54, as shown in FIG- URE 2,serves as a control arm having legs 56 and 58 that converge at a vertexportion 60 while the opposite ends of the respective legs areinterconnected by a web 62. The vertex portion 60 is connected through aspherical pivot connection 64 to a depending bracket 66' fixed with theframe 20 of the tractor. The other ends of the legs 56- and 58 extendforwardly and are pivotally mounted to the axle housing 52 by pivotjoints 67 and 68, respectively located above and below the axis of wheelrotation. As shown in FIGURES and 6, the A-frame members 54 lie ininclined intersecting planes that are transverse of the axis of wheelrotation. This manner of supporting an axle housing as well as theconstruction of the A-frame members is identical to that shown in US.Patent No. 3,177,066, in the name of R. L. Knight, and entitled AxleControl Arm For Vehicle Suspension, and reference is made to that patentfor a further description and better understanding of the design andconfiguration of the control arms associated with axle housing 52.

The axle control linkage also includes a pair of hydraulic cylinders 70located forwardly of the axle housing 52 and each having the cylinderportion thereof universally pivotally connected to the front end of theframe 20 by a spherical connection 72. The piston rod of each cylinder70 extends downwardly for universal pivotal connection by a sphericaljoint 74 with a projection 76 rigid with the axle housing 52. As in thecase of the control arms, each of the hydraulic cylinders is locatedadjacent to one end of the axle housing 52, and it will be understoodthat the cylinders 70 are adapted to be operated by a suitable hydrauliccircuit for coordinated or selective expansion and contraction forpurposes to be described below. The hydraulic circuit and valvingrequired to operate the cylinders 70 are well known to those skilled inthe art and, therefore, detailed discussion thereof is not required foran understanding of the invention. However, it will be noted that in thepreferred form, each of the cylinders 70 is of the double-acting typehaving a relatively reciprocable piston rod and cylinder member, thelatter of which obtains pressurized fluid at one end while exhaustingfluid from the other end. When not being activated, the fluid in eachend of the cylinder is locked therein so that the cylinder 70 serves asa rigid link member.

The A-frame suspension arrangement for the axle housing 52 together withthe hydraulic cylinders 70 permit the height of the pivot connection 28and accordingly the front portion of frame 20 to be varied relative tothe ground. In other Words, the front end of the vehicle can be raisedor lowered and, in this connection, it will be noted that, as seen inFIGURE 3, when the hydraulic cylinders 70 are jointly contracted, theaxle housing 52 in effect moves clockwise under the control of the A-frame members 54 about the pivot connections 64 and the front of theframe is lowered relative to the ground. When the axle housing 52assumes this position, the bucket 22, of course, is then located at adigging depth greater than normally provided by the loader vehicle.

4 Similarly, as shown in FIGURE 4, when the hydraulic cylinders 70 arejointly expanded to their full extent, the axle housing 52 moves awayfrom the frame 20 causing the latter to be raised so as to increase thedistance between the pivot connection 28 and the ground. At this time,when the boom 24 is raised to the dump position, increased dumpingheight is realized. Thus, it can be seen that by coordinated contractionand expansion of the hydraulic cylinders 70, the dump height and diggingposition of the loader can be increased.

Another feature of the invention described above is that by propercontrol of the individual hydraulic cylinders 70, the bucket 22 can betilted about the longitudinal axis of the vehicle. In this regard,attention is directed to FIGURE 6. It will be noted that by expandingone of the cylinders 70 and contracting the other, the vehicle frame 20and accordingly the bucket 22 can be leaned to one side or the other soit can be used for crowning, sidecasting, or ditching operations. This,of course, can be realized because, as aforedescribed, the rear axle 16is supported for free movement about a longitudinal axis and, therefore,the vehicle frame 20 can be tilted until encountering the mechanicalstops normally associated with the axle.

Various changes and modifications can be made in this constructionwithout departing from the spirit of the invention.

I claim:

1. In combination with a vehicle supported by longitudinally spaced andtransversely extending front and rear axles, the forward end of saidvehicle having a boom equipped with a bucket movable between fixedlimits constituting a lowered-dig position and a raiseddump position,power-operated means extending between the boom and the bucket formoving the latter relative to the boom, the improvement comprising meansextending rearwardly from the front axle and connecting the latter tothe vehicle for pivotal movement about a transverse horizontal axis, andfluid operated adjustable means connected between said front axle andsaid vehicle for effecting said pivotal movement whereby the elevationof said forward end of the vehicle can be varied to increase said fixedlimits.

2. A rubber-tired front end loader comprising, a tractor supported bytransversely extending front and rear axles, the forward end of saidtractor pivotally supporting a boom for movement about a firsttransverse axis, the free end of said boom supporting a bucket forrotation about a second transverse axis, power-operated linkageextending between said boom and said bucket for controlling movement ofthe latter about its support axis with the boom, means connected to saidboom for moving the latter about said first transverse axis betweenfixed limits defining a lowered-dig position and a raised-dump position,control arm means extending from said front axle and connecting thelatter to the tractor for pivotal movement about a third transverseaxis, and power-operated adjustable means connected between the frontaxle and the tractor for effecting said pivotal movement of the frontaxle whereby the elevation of said forward end of the tractor is variedto increase said fixed limits.

3. A rubber-tired front end loader comprising, a tractor supported bytransversely extending front and rear axles, said rear axle beingconnected to said tractor for free oscillation about a substantiallyhorizontal axis extending longitudinally of the tractor, the forward endof said tractor pivotally supporting a boom for movement about a firsttransverse axis, the free end of said boom supporting a bucket forrotation about a second transverse axis, power-operated means extendingbetween said boom and said bucket for controlling movement of the latterabout its support axis with the boom, means connecting the front axle tothe tractor for movement about a second substantially horizontal axisextending longitudinally of the tractor, and power-operated adjustablemeans connected between the front axle and the tractor for effectingcontrolled movement of the front axle about said second substantiallyhorizontal axis whereby the tractor and the bucket are tilted so thatone side edge of the latter is higher than the other side edge.

4. The loader of claim 3 wherein said means connecting the front axle tothe tractor comprises first and second A-shaped control arms, each ofsaid arms having the vertex portion thereof universally pivotallyconnected to the frame and the spaced arms thereof pivotally connectedto the axle at spaced points located above and below the axis of wheelrotation, said spaced pivot points defining a common pivot axis that isinclined to the vertical and lies in a plane transverse to the axis ofwheel rotation.

5. A- rubber-tired front end loader comprising, a tractor supported bytransversely extending front and rear axles, said rear axle beingconnected to said tractor for free oscillation about a horizontal axisextending longitudinally of the tractor, the forward end of said tractorpivotally supporting a boom for movement about a first transverse axis,the free end of said boom supporting a bucket for rotation about asecond transverse axis, power-operated means extending between said boomand said bucket for controlling movement of the latter about its supportaxis with the boom, means connected to said boom for moving the latterabout said first transverse axis between fixed limits defining alowered-dig position and a raised-dump position, means connecting thefront axle to the tractor for pivotal movement abozut a pair of mutuallyperpendicular axes, power-operated adjustable means connected betweenthe front axle and the tractor for eflecting movement of the front axleabout one of said mutually perpendicular axes whereby the elevation ofsaid forward end of the tractor is varied to increase said fixed limits,and for effecting movement of said front axle about the other of saidmutually perpendicular axes whereby said bucket is tilted so that oneside edge of the latter is higher than the other side edge.

6. The loader of claim 5 wherein said means connecting the front axle tothe tractor comprises first and second control arms respectively locatedon each side of the longitudinal axis of the tractor and having threespaced connecting portions formed on each of said arms, means pivotallysupporting two of said connecting portions of each arm on said axleabout a common pivot axis that is inclined to the vertical and lies in aplane transverse to the axis of wheel rotation, said last-mentionedmeans being located at spaced points above and below the axis of wheelrotation, and means universally pivotally supporting the thirdconnecting portion of each arm on said frame at a point longitudinallyspaced from first-mentioned means.

7. The loader of claim 5 wherein said power-operated adjustable meansincludes a pair of double-acting hydraulic cylinders, each of which islocated adjacent one end of the front axle.

References Cited UNITED STATES PATENTS 2,711,257 6/1955 Apel 214-7763,177,006 4/1965 Knight 280-124 HUGO O. SCHULZ, Primary Examiner.

US. Cl. X.R.

